SEATTLE -- Nationals third baseman Ryan Zimmerman had an MRI on Monday and the results yielded good news, according to manager Matt Williams. Zimmerman's right hamstring is healing nicely. He has already started jogging and has been throwing every other day.

Zimmerman's first test will be running at full speed, then running around the bases and finally taking batting practice, according to Williams.

"He is making the progress that he should make," Williams said. "The strength will increase now that he could start pushing it. ... Once he feels good about that, he can get out and start running and doing some sprint work, all the while being mindful that you don't want to push it too hard. If you lose him, you lose him for good at this point."

Williams said recently that he hopes to get Zimmerman back on the field by late September. However, no timetable has been set -- yet. Zimmerman sustained a Grade 3 hamstring strain, which takes a while to heal.